The present invention relates generally to electric vehicles and, more particularly, to an integrated power electronics cooling housing for use in a power electronics system.
The assignee of the present invention manufactures electric vehicles. The electric vehicle comprises a power electronics system that is used to distribute electrical power to various components in the vehicle.
Prior art related to cooling of power electronics systems involves liquid cooling of power semiconductor devices using a discrete heat exchanger electrically connected to a chassis, combined with air cooling of other dissipating components (either directly to air or by conduction to chassis and air cooling of the chassis). Disadvantages of conventional cooling arrangements are as follows.
The heat exchanger is only used once for the power semiconductor devices. Air cooling of other heat-dissipating components is less effective than cooling provided by a liquid cooling path, which results in higher operating temperatures and lower reliability. The capacitance of the power semiconductor devices relative to the chassis is higher, which results in higher injected currents that generate electromagnetic interference (EMI).
It would, therefore, be desirable to have an integrated power electronics cooling housing for use in a power electronics system such as may be used in an electric vehicle, for example, that overcomes the limitations of conventional implementations.
The present invention comprises a power electronics cooling housing for use in a power electronics system. The power electronics cooling housing comprises a body having a coolant cavity formed in one surface and having a capacitor bus assembly potting cavity formed in an opposite surface. A bus bar passthrough opening is formed through the body. The bus bar passthrough opening provides an opening from the coolant cavity and the capacitor bus assembly potting cavity. A coolant inlet manifold having a coolant cavity inlet and a coolant outlet manifold having a coolant cavity outlet are formed in the body that are coupled to respective ends of the coolant cavity. An environmental sealing gasket surrounds the coolant cavity.
All power-dissipating components coupled to the housing are liquid-cooled by the same coolant loop. The housing is designed to accept a thermal plate and environmental sealing gasket for use with high power dissipating devices. The housing has coolant inlet and outlet ports, a coolant cavity, thermal interfaces and component mounting and potting features. Low power-dissipating devices are cooled through the housing by the coolant cavity. The housing is designed for automotive and other dynamic environments. The housing is designed to have a minimal part count and a low number of electrical interconnects to provide higher reliability. All electronic components may be electrically isolated from the chassis for EMI shielding and safety if the housing is made of dielectric material.